Muffler with single outlet opening elongated in a direction parallel to the axis of the inlet opening



Nov 18, 1952 G H HEDR|K 2,618,355

MUFFLER WITH SINGLE OUTLET OPENING ELONGATED IN A DIRECTION PARALLEL TOTHEAXIS OF THE INLET OPENING Original Filed Sept. 10, 1943 3Sheets-Sheet l Gale floll z-obk edrick Nov. 18, 1952 HEDRlcK I 2,618,355

MUFFLER WITH SINGLE OUTLET OPENING ELONGATED IN A DIRECTION PARALLEL TOTHE AXIS OF THE INLET OPENING Original Filed Sept. 10, 1943 5Sheets-Sheet 2 NOV. 18, 1952 HEDR|K 2,618,355

MUFFLER WITH SINGLE OUTLET OPENING ELONGATED IN DIRECTION PARALLEL TOTHE AXIS OF THE INLET OPENING Original Filed Sept. 10, 1945 3Sheets-Sheet 3 Gale HolbrooK lqechitk patented Nov. 18, 1952 MUFFLERWITH SINGLE OUTLET OPENING ELONGATED IN A DIRECTION PARALLEL .TO THEAXIS OF THE INLET OPENING Gale H. Hedrick, Chicago, 111., assignor toMarcmont Automotive Products, Inc., Chicago, 111., a corporation ofIllinois Original application September 19, 1943, Serial No. 501,874.Divided and this application August 5, 1948, Serial No. 42,687

10 Claims.

The present invention relates to improvements in 'muiilers for internalcombustion engines.

The primary object of the present invention consists in providing amuflier with means for reducing the velocity of the exhaust gasesdischarged to the atmosphere. This means comprises forming the mufilerwith an inlet opening and an elongated outlet opening or slot. Theseopenings are so proportioned that the crosssectional area of the outletopening is always equal to or greater than the cross-sectional area ofthe inlet opening or openings to insure the exhaust gases discharging atlow velocity from the mufiier.

Another object comprehends the provision of a muffler of any suitableshape having an elongated outlet opening with which coacts baflle meanspositioned within the mufller for reducing the velocity of the gases asthey enter the atmosphere.

A further object is to provide a muffler in which the velocity of gasesintroduced to the atmosphere is so markedly reduced as to (l) preventflaming of the exhaust, (2) dilute and cool the exhaust gases topreclude condensation, (3) eliminate the blowing of oil particles andcarbon out of the xhaust and l) preclude the discharge of obnoxiousodors.

The muiiler is arranged to be used with any type of internal combustionengine and when associated with a vehicle or an airplane is preferablypositioned so that the exhaust gases are liberated tothe atmosphere inthe slip stream to create a suction effect upon the exhaust line whichsubstantially reduces back pressure. The improved form of muffler alsomaterially increases the efiiciency of a supercharger and in someinstances dispenses with the use of the same.

Other objects and advantages of the invention will become apparent fromthe following description when taken in conjunction with theaccompanying claims and drawings.

Referring to the drawings in which are shown several preferredembodiments the invention may assume:

Figure l is a detail side view of an airplane showing one form of theimproved muffler associated therewith;

Figure 2 is an enlarged plan view of the muffler shown in Figure 1;

Figure 3 is a rear view of the mufller shown in Figure 2, viewed at oneend;

Figure 4 is a sectional view along line 4--4 of Figure 3;

Figure 5 is a detail side-view of a baffie member;

Figure 6 is a detail perspective view of spacer bars for the walls ofthe muffler at the exhaust outlet;

Figure '7 is a plan view of a modified form of the invention;

Figure 8 is a longitudinal sectional view of Figure '7;

Figure 9 is a detail enlarged end view of Figure 8;

Figure l0 is a sectional view taken substantially along line |fll0 ofFigure '7;

Figure 11 is a plan view of a further modified form of the invention;

Figure 12 is a longitudinal sectional view of Figure 11;

Figure 13 is a sectional view taken substantially along line 13-!3 ofFigure l2;

Figure 14 is a detail side elevation of the clamping member; and

Figure 15 is a detail longitudinal sectional view of a clamping member.

Referring to the drawings, the muffler l-U is disclosed in Figure 1associated with the exhaust manifold ll of an airplane motor, and may besuitably carried by the fuselage 12 or the wings [3, so as to bepositioned in the slip stream of the propeller P. As shown, the muffleris connected to one of the wings l3 and is shaped so as to conform tothe curvature of the wing.

Th mufiler is constructed and arranged to be used with any type of motorpropelled vehicle for the purpose of providing simple, efficient, andeconomical means for reducing the velocity of the exhaust gasesdischarged to the atmosphere.

Preferably the muffier to is of streamlin form and has a top orconcave'wall I4 (Figure 4), a front inclined wall 15, and a horizontalbottom wall 16. It will be observedthat these three walls constitute acasing which in crosssection is of substantially triangular shape and inwhich the walls 15 and 16 are connected at an obtuse angle, and thewalls 14 .and I 5 are connected at an acute angle. The walls 14 and I6converge rearwardly as shown to form at the trailing side or edge, anelongated exhaust outlet opening or slot ll of reduced width withrespect to th inlet opening and which preferably extends the length ofthe casing. Spaced channel members l8 and I9 are positioned in the mouthof the opening 11 to maintain the walls l4 and [6 in proper spacedposition.

The opposite ends I 0 of the mufiier l 0 are provided with alignedopenings 20 through which extend in sealed relation the inlet pipes 2|.Each of the inlets 2i communicates with the exhaust 3 manifold II and issuitably secured thereto as at 22 (Fig. 1).

The length of the mufiier l and the dimensions of the elongated outletexhaust opening or slot ll are so proportioned relative to the inletopenings 20, that the total cross-sectional area of the outlet opening His at least equal to and preferably greater than the totalcross-sectional area of the inlet openings 28, whereby a positivereduction in the velocity of the exhaust gases as they discharge throughthe opening I? to the atmosphere is achieved.

The interior of the mufiler casing 50 toward the rear thereof andbetween the inlet openings 20 and the outlet exhaust opening I1 isprovided with a V-shaped or U-shaped baffle or gas-retarding member 23.This member is preferably formed from a metal blank which in the presentinstance is bent medially to provide inclined sides 2 connected at theirrespective longitudinal edges to the walls id and I6 as shown, the saidsides converging rearwardly toward the opening or slot ll, so as to meetat 25 (Fig. 4). This bafiie member preferably extends the length of themuffler and substantially parallel to and coextensive with the exhaustoutlet opening ll. Perforations 26 are formed in the baffle to allow theexhaust gases delivered into the casing to be discharged to theatmosphere through said outlet.

Disposed within the casing on the inlet side of the baflle member 23 area plurality of transversely extending plates or bafiles 2? shown indetail in Figure and having top, side and bottom edges suitablyconnected to and conforming in shape to the interior of the casing, i.e., the top, side and bottom walls. These plates 27 are spacedlengthwise of the casing to divide the forward end thereof into a seriesof eXpansion chambers or compartments 28 (Figs. 2 and 5). Each of theplates 21 is preferably formed with a tapered rear edge 29 (Fig. 5)conforming to and arranged to engage the complementary inclined sides 24of the baffle member 23, so as to constitute a support, and reinforcingmeans therefor throughout the length of the mufiler. In this manner,each expansion chamber 28 has its rear wall constituted by bafile 23.

The tapered plates 21 at their enlarged portions are provided withopenings 36 of substantially the same diameter as the openings 28 anddisposed in substantially longitudinal spaced relation with the openings30 are smaller openings 3! each arranged to establish communicationbetween the respective chambers or compartments 28. The openings 36 inthe bafiies or partitions 21 disposed adjacent the ends of the mufflerreceive the pipes 2| and coact with the end walls 19 to support thepipes.

In operation, the exhaust gas from the manifold I l discharges at highvelocity into the muiller [0 through the inlet pipes 2|. A part of thegas passes through the adjacent bafile member 23 to the atmospherethroughthe elongated opening ll. Another part of the exhaust gas isconducted first through the opening 38-3! in the plates 27 to theexpansion chambers 28 and then discharges through the adjacent baiilemember 23 into the outlet IT to the atmosphere. Due to the fact that thearea of the opening I? is greater than that of the inlet openings 20,the gases discharge through the outlet or exhaust opening IT at lowvelocity. While the muiiler I0 is shown provided with inlet pipes 2| atopposite ends thereof, it will be manifest that only one inlet pipe maybe used without in any way interfering 4 with the otherwise efi'icientoperation of the muffler. That is, in all constructions of the muiiler,the cross-sectional area of the inlet 20 will be less or not greaterthan equal to that of the area of the outlet ll, so as to cause thegases to discharge at low velocity to the atmosphere in a cool anddiluted condition. The perforated baflle member 23 coacts with theoutlet opening H to retard the velocity of the gases discharging fromthe muffler and insures the gases being directed into and expanded andcooled in the compartments 28 before they enter the atmosphere, thusreducing or eliminating flaming of the exhaust. The elongated outletopening ll also tends to eliminate obnoxious odors and the blowing'ofoil particles and carbon out of the exhaust onto the clothing ofpassersby. The presence of the bafiie structure in the muiiler casingconstitutes the latter as a resonating chamber, thereby reducing thenoise in a highly desirable manner.

The mu'liier casing I6 is wherever possible positioned in the slipstream of the vehicle, 6. g., of the airplane propeller P, which createsa suction around the outlet 17, acting to draw the exhaust gases throughthe muffler H], and thus prevent objectionable back pressure. In thecase of other types of vehicles such as automobiles, trucks andtractors, the muflier is equally effective to discharge exhaust gases ata low velocity and eliminate back pressure.

In the modified form of the invention shown in Figures '7, 8, 9 and 10,a muffler 33, preferably of elliptical or oval shape, is arranged tocommunicate with the exhaust of an internal combustion engine throughthe inlet pipes at having elbows 35 extending outwardly from op ositeends.

of the muffler and to which are connected a tube 36 disposed within themuffler and coextensive in length therewith. I i

The elliptical casing 33 is provided with an elongated narrow opening orslot 3? extending the length of the muffler, and having an outwardlyflaring mouth defined by the angle iron members. 38 which extendthroughout the length of the opening 31. These members are welded orotherwise secured to the casin 33 and extend outwardly therefrom onopposite sides of the opening 3i as shown. The length of the muffler orcasing 33 and the size of the outlet opening 3'! are so proportionedrelative to the diameters of the inlets as that the cross-sectional areaof the outlet 3? is equal to or greater than the cross-sectional area ofthe inlets so as to reduce the velocity of the gases discharged from themuiiler.

The tube 36 has its surface remote from the elongated outlet 31 providedwith perforations 39 preferably extending half-way around the tube toretard the velocity of the exhaust gases which discharge into theexpansion chamber 58 formed between the elliptical casing 33 and thecylindrical tube 36. The exhaust gases, as they enter the chamber 4%,are expanded and cooled and then discharged through the side outlet 31at a low velocity and are also freed from obnoxious odors. The tube 38is maintained in proper spaced position relative to the casing 33 by therings or web members il havin perforations 41' which allow the exhaustgases to circulate freely through the chamber 48. If desired, one end ofthe mufiler could be closed so that the exhaust gases enter the muffleronly through a single inlet 34. The tube 36 and web members 6! form asuitable bafile structure in this form of mufiler.

In the modified form of the invention shown in Figures 11 to 15,inclusive, themufiler casing; 42 f is of substantially elliptical formand is provided at one end with an inlet 43 and has its opposite end 44closed. An elongated outlet or discharge opening 45 is formed in oneside of the casing and extends the length thereof. Spaced angle ironmembers lit defining an outwardly flaring mouth for the opening 45 arewelded or otherwise secured to the wall of the casing. A tube i? extendslengthwise of the casing and has a portion projecting outwardly throughthe inlet opening 43 so as to be connected to an exhaust inlet pipe 28preferably by the clamping means 59 shown in Figure 15. This clampingmeans comprises a pair of spaced curved or segmental upper and lowerstrap members 58 and 5!, respectively (Fig. each of which has a mediallydisposed annular rib 52 from which extend outwardly the flat expansiblearms 53. Curved saddle members 54 engage the arms 53 and are spaced fromeach other by the rib 52. The members 54 have spaced vertical openings55 through which extend the flexible U-shaped clamping rods 56 thatengage the lower members 55, and have their upper threaded end portions5? arranged to extend through the openings 55 to receive the clampingnuts 58 for releasably securing the tube i! to the inlet pipe 48 andthus provide a firm, tight seal when the parts are set up.

The tube 4'! has its surface remote from the outlet opening 45 formedwith perforations 59 through which the exhaust gases from the enginedischarge into the expansion chamber so formed between the interior ofthe casing and the tube ll. Spaced webs 6| are positioned between thetube 41 and the inner wall of the casing 42 so as to maintain the partsin proper spaced position and are provided with openings $2 for allowingthe free circulation of the exhaust gases within the chamber 36 prior tothe discharge of these gases to the atmosphere through the restrictedelongated opening 2.5. The cross-sectional area of the outlet is sopositioned as to be at least equal to and preferably greater than thecrosssectional area of the inlet 43 discharging into the murder. Thetube 4? and webs 6| constitute the baffle structure in this form ofmuiiler.

The muilier 62 may be connected to the exhaust of an internal combustionengine on any type of motor vehicle such as an automobile, airplane, or

the like, by the flanged brackets 52, retaining bolts 63, and nut ti i-(Figure 12) While the discharge openings 37 and iii, respectively, ofthe Inufilers shown in Figures 10 and 13 are located parallel with themajor axis of each of the casings 33 and 42 to discharge the gasessubstantially horizontally with respect to the ground, the mufiiers maybe so positioned or the discharge openings so disposed that the exhaustdischarges either upwardly or downwardly with respect to the ground andaway from the motor, depending upon the particular type of vehicle inwhich the muiiler is associated.

It will be observed that in all forms of the invention the length andwidth of the exhaust outlet in the mufiler has a cross-sectional areaequal to or greater than the cross-sectional area of the inlet orinlets, so that the exhaust gases will discharge at low velocity to theatmosphere. Moreover, each of the mufflers is provided with bafile meansfor causing the exhaust gases to lose velocity while circulating throughthe muffler and also the gases are permitted to expand and cool beforebeing discharged to the atmosphere at low velocity. The gases introducedto the atmosphere are subjected to dilution, due to the nature of theoutlet, whereby the exhaust gases are more readily mixed with theatmosphere than if they were exhausted through a round pipe at highvelocity. Also, the several mufllers with their baffle structures form,in effect, resonating chambers to eliminate noise. Further, the shapeand size of the exhaust outlet is such that when the muiller isassociated with a motor vehicle or an airplane, it may be positioned inthe slipstream, so as to produce a low pressure area about the outletand eliminate back pressure, thereby increasing the eificiency of themotor.

It will be understood that the several forms of the invention shown aremerely illustrative of preferred embodiments, and that such changes maybe made as fall within the purview of one skilled in the art withoutdeparting :from the spirit of the invention and the scope of theappendedclaims.

This application is a division of my allowed copending application,Serial No. 501,874, filed September 10, 1943 now Patent 2,457,890.

I claim:

1. A mufiier comprising a casing provided with an inlet opening at oneend, a single outlet open ing elongated in a direction parallel to theaxis of the inlet opening to extend substantially the length of saidcasing, the outlet opening being of reduced dimension in a directionnormal to said axis, the cross sectional area of the outlet openingbeing at least equal to that of the inlet opening so as to reduce thevelocity of the gases discharged through the outlet opening.

2. A mufiler comprising a casing provided with an inlet opening at oneend, a single outlet opening elongated in a direction parallel to theaxis of the inlet opening to extend substantially the length of saidcasing, the outlet opening being of reduced dimension in a directionnormal to said axis, the cross sectional area of the outlet openingbeing greater than that of the inlet opening so as to reduce thevelocity of the gases discharged through the outlet opening.

3. A muffler comprising a casing provided with an inlet opening at oneend, a single outlet opening elongated in a direction parallel to theaxis of the inlet opening to extend substantially the length of saidcasing, the outlet opening being of reduced dimension in a directionnormal to said axis, the cross sectional area of the outlet openingbeing greater than that of the inlet opening, and means within thecasing coacting with the outlet opening for reducing the velocity of thegases discharged to the atmosphere.

4. A muffler comprising a casing provided with an inlet opening at oneend, a single outlet opening elongated in a direction parallel to theaxis of the inlet opening to extend substantially the length of saidcasing, the outlet opening being of reduced dimension in a directionnormal to said axis, the cross sectional area of the outlet openingbeing greater than that of the inlet opening so as to reduce thevelocity of the gases discharged through the outlet opening, and bafflemeans within the casing between the inlet opening and outlet opening andcoacting with the outlet opening for reducing the velocity of the gasesdischarged to the atmosphere.

5. A muffler comprising a casing provided with an inlet opening at oneend, a single outlet opening elongated in a direction parallel to theaxis of the inlet opening to extend substantially the length of saidcasing, the outlet opening being of reduced dimension in a directionnormal to said axis, the cross sectional area of the outlet openingbeing greater than that of the inlet opening so as to reduce thevelocity of the gases discharged through the outlet opening, andperforate bafile means within the casing between the inlet opening andoutlet opening and coacting with the outlet opening for reducing thevelocity of the gases discharged to the atmosphere.

6. A muffler comprising a casing having an in- ,7. A mufiler comprisinga casing havingany inlet opening in at least one end and an elongatedoutlet opening of reduced Width with respect to the inlet in the sidethereof, the cross-sectional area of the outlet being at least equal tothat of the inlet so as to reduce the velocity of the gas dischargedthrough the outlet, an angular perforated plate within the casingbetween the inlet and outlet openings, and spaced bafiles extendingtransversely within the casing and positioned on the inlet side of saidplate for providing the casing with communicating chambers, said plateand baflles coacting with the elongated outlet opening for reducing thevelocity of the gases discharged to the atmosphere.

8. A muffler comprising a casing of a streamline form having an inletopening in at least one end and an elongated outlet openin of reducedwidth with respect to the inlet in the trailing side thereof, thecross-sectional area of the outlet being at least equal to that of theinlet so as to reduce the velocity of the gas discharged through theoutlet, a perforated plate within said casing extending lengthwisebetween the inlet and outlet opening, and spaced perforated bafliesWithin the casing and extending transversely thereof to formcommunicating compartments on the inlet side of said plate, said plateand bailies coacting with the elongated outlet opening for reducing thevelocity of the gases discharged to the atmosphere.

9. A mufiler comprising a casing having an inlet opening in one end andan elongated outlet opening of reduced width with respect to the inletin the side thereof, the cross-sectional area of the outlet being atleast equal to that of the inlet so as to reduce the velocity of the gasdischarged through the outlet, and a tube communieating with the inletopening extending lengthwise Within the casing in spaced relation to thewall thereof and between said openings, said tube having perforations onthe side thereof remote from the outlet opening and ooacting with theoutlet opening to reduce the velocity of the gases discharged to theatmosphere.

10. A muiiler comprising an elliptical casing having an inlet opening inat least one end and an elongated outlet opening of reduced width withrespect to the inlet in the side thereof, the cross-sectional area ofthe outlet being at least equal to that of the inlet so as to reduce thevelocity of the gas discharged through the outlet,-

a tube extending lengthwise in said casing in spaced relation to theWall thereof and communicating with the inlet opening, said tube havingperforations in the side thereof remote from the outlet opening, thespace between the tube and the elliptical casing constituting anexpansion chamber coacting with the elongated outlet opening forreducing the velocity of the exhaust gases discharged to the atmosphere,and perforate baffie members in said chamber extending about said tube.

GALE H. HEDRICK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 681,522 Very Aug. 27, 19011,032,794 Wolf July 16, 1912 1,556,934 Hilldring Oct. 13, 1925 1,922,825Squires Aug. 15, 1933 2,343,371 Fisher Mar. 7, 1944 2,457,890 HedrickJan. 4, 1949 FOREIGN PATENTS Number Country Date 25,642 Great BritainNov. 14, 1896 of 1896 657,569 France May 24, 1929

